18" Proof Research - 6mm ARC build and testing - factory and handloaded ammo
#21
(08-15-2020, 12:43 AM)Trashy Wrote: Dang PP, sorry to hear you had such bad first range day.  Not trying to add insult to injury but I have shot 170 rounds of the 105’s through my cmmg barrel without incident.    Do you have a hornady oal gauge?  if you do let me know, I have a modified case for the arc, just have to work out the details to get it to you so you can measure that chamber good. 

Trashy

Hey Trashy

Thanks for the offer but no I don’t have an OAL gauge and if my throat is in the short side I will just forego using 105s for the moment till my McGowen barrel is ready.

I shot the Proof again today , didn’t bother writing down velocity it was pretty much the same as the other day.

Both groups were under 1”
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#22
Guy I follow on instagram n YouTube for a SanTan ARC with a proof carbon fiber barrel and I told him about the 105's and he said he had the problem the problem too. Either Proof hasn't chambered the barrels right or Hornady has screwed up!

Either way someone dropped the ball and is going to mess with a promising cartridge from the go!

Have you reached out to Proof n Hornady Yet?
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#23
I sent Proof the video and asked for their thoughts - they haven’t responded or confirmed receipt of the message.

I’m not going to bother Hornady - what would you think they would say to just a guy who shoots - being they’re the Father of the Caliber.....

I’m sure we just aren’t doing something right (sarcasm)
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#24
I just got off the phone with Hornady.

They are not completely putting ODIN and Proof in the hot seat - the tech says they could stand to shorten the COAL for the 105 BTHP Black ammo.

He says what most likely happened is that Hornady sent “high speed reamers” out to barrel makers, these reamers are good for only 10-15 chambers (they are non-carbide).

It may be that these gun manufacturers went in to full production with these high speed reamers and so early runs of barrels can be short or tight in the throat.

He says I can seat the factory loads deeper to use what I have and I said no thanks.

He said maybe chasing the throat with a carbide reamer will fix my barrel and I said I wouldn’t want to do that to a 500 barrel.

So now waiting for proof to respond....

Update again - proof responded , they don’t have any 105 BTHP on hand to test barrels with, they requested photos of a chambered round which I will send to them shortly.

Meanwhile....  I talked to another barrel maker who is working on a barrel for me and they said they’re aware of the “issue” and they think the bullet diameter of the 105 grain BTHP is towards the higher end of tolerance.....

Continuing to trouble shoot this .
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#25
I am with your barrel guy's thought. I have the tools to measure bullets and chambers. The Hornady 105's are a little on the fat side. I can load the Nosler 105 to the exact length of the Hornady's and they do not contact the rifling. I can use a bullet comparator and the dimension is different between them. They are the same at the olgive, but the olgive to the tip is wider. Now if I compare the Nosler 105 dimensions to the Hornady 108's they are the same. My take on this it is a bullet design issue.


I will add that I have three barrels, 2 Faxon, and the Odin. The Odin chamber is the shortest of them but not by much, less than .020. So what ever I load my lead jump will be less. This is not enough to be a huge problem, as the only bullet that I am aware of that is an issue is the Hornady 105. But they can be loaded deeper into the case which is not a problem as long as the case will accept my powder charge.


I ordered some more 105's today, hopefully they are the new ones, but from what I was told by Hornady they were not going into production until the middle of the month. That time is here, but I find it hard to believe that they are hitting the shelves yet, I could be wrong though.
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#26
I need a little help here. When you say “fatter” or “bullet diameter on higher side”... this speaks to diameter, but some of what’s being said speaks to the stubby shape of the bullet tip ogive-tip. Anyone use a micrometer on their stash? Saying the comparator strikes higher or lower on the bullet, again that’s about the forward shape not diameter, which still hopefully is 0.243.
Sleekness in the front, that will definitely affect seating coal/hitting lands, but why isn’t the actual leade/chamber throat area the real issue?
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#27
The olgive is the point on the bullet were it transitions to the tip, in other words the taper as you put it. Thats where the problem is.

The other side of the olgive is where it transition from the taper to bullet body. In other words the .243 part of the bullet that gets seated into the neck of the case.

The olgive is the point on the bullet where it goes from a straight wall to the taper, it is the breaking tangent point.
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#28
That's what I understood. It's just that terms like "fatter" bullet imply to me that the 0.243 diameter is out of spec. I think what everyone is saying is, the 105 has a "stubbier" (my term) front-part, ie, ogive and forward. Traditional bullet tapers are "tangent" profile, while sleeker ones have "secant" or hybrid tan-secant style, longer tapers... again, if my old retired brain is tracking this ok. The 105 is probably the tangent style, whereas the 108 is secant style.
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#29
Thumbs Down 
Here is what is going in with the 105 BTHP load and my PROOF chamber.

BEFORE CHAMBERING:

   

AFTER CHAMBERING:  I carefully used a cleaning rod down the breach while pulling firmly on the charging handle to get it to unstick without leaving the bullet behind

   

Looks like the hang up is in the area of the freebore based on this cutaway illustration

   

I don't wish to have my current chamber "chased" or opened up, at least not on a $ 500 investment.....
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#30
Do the same thing with a 108 and post pics. That was way worst than what I was seeing.

I think that camber needs to be chased with a reemer.

The top angled mark looks like where its hitting the riffling, the other marks look like tool mark chattering in the chamber.

What is the OAL of that round?
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#31
My .02 is that it needs to go back to Proof for a few refinements.

Trashy
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#32
Sent you a PM
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#33
That’s been my feeling all along, the freebore I guess it’s called. Anyway the 6arc has a 1.5* slope after the freebore so that most bullet ogives will work. (Correct my terminology if wrong). See the saami drawing. Those transverse stripes look pretty bad imo, now I’m not a gunsmith however. But a brand new barrel?? Come on.
There’s supposed to be 0.090 straight freebore then 0.125 sloped at 1.5* (*= degree sign).
You may or may not have the 0.090 before the tool chatter starts, but I’d bet some Dunkin’ Donuts you don’t have the proper sloped portion.
In my faxon the 103 can go out to 2.280 iirc but it has the sleeker ogive profile.
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#34
Pig_Popper that is some weirdness to be sure. It's hard to picture what could make the throat of that barrel make marks like that, the process of removing the reamer from the spinning barrel would not make parallel marks, a chipped reamer would make a spiral? If you wanted to make a throat that made those marks the only way I can think of to do it would to use a boring bar and make a small cut, back it out and pull it back then make another cut and so forth.
Keep us posted on the mystery!
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#35
Their is some bad juju going on in the lead and freebore of that chamber. When the bolt goes into battery the bullet is spun about 1/8 of a turn and that is when you get the marking.

My Odin has the same issue, but only with 105's, but it only has the mark like yours the one towards the tip, the one that is slanted. But it's not as bad. If I set the bullet back .010 it works fine, so I had to go from 2.245 factory OAL to 2.235 and it functions as it should. It's to bad that two top tier manufactures are having this issue, but I don't believe it is totally their fault. Hornady is going to have to own up to some of this if they sent the wrong tooling.

Send that thing back and get it fixed. I know when I get my new factory 105's, and I still have the problem with it, mines going back.
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#36
NOT MY VIDEO :



At minute mark 6:17 the guy bore scopes the area I am getting interference at on my barrel.

I don’t see anything obvious on his bore scope to explain the spaced concentric rings on my bullets...

The barrel will go back when I have another in hand to replace it - I can be load developing with my 90 grain bullets with this barrel (checking velocities and powders out) with no detrimental effects.

I absolutely agree, the “heavy players” in the industry shouldn’t be experiencing these problems on a product launch.

Very disappointing !

One point I would like to discuss - I found the following article that talks about the importance of freebore dimensions - it is from this line of thought that I just don’t prefer to mess with a chamber that has been set by the initial reamer and polishing - metal can never go back ...  would rather have a unit that was done right the first time.

Keep in mind , the issue appears to be with the shape of 1 bullet tested thus far , modifying a currently chambered barrel (that may not be to spec) and is for a bullet that I don’t plan to shoot seems like the same as saying two negatives make a positive in math , it just doesn’t add up for me.

   
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#37
Chances are they will replace it. the problem looks to be excessive metal.

They will probably not reem it, but hone it which will only remove the high spots.

Proof is a reputable company, I'm sure they will do you right.

Like I said I have some of the new ammo coming, and if I still have the issue I will send mine back.

You need to get a couple of tools for your reloading arsenal, especially if you are reloading for accuracy. A bullet comparator, and an OAL gauge. You will need a modified case .That has been OOS for a long time, but I will make you one for no charge and send it to you.

These are must have's in precision reloading and not very expensive. Another reason you need it just like me you have a tight chamber, not a bad thing in presion shooting. But with these tools you will be able to tailor your reloads to your riffle with repeatable results. You will also be able to monitor barrel wear and tailor you reloads to the wear.
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#38
Well said Dino!!!
Trashy
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#39
Something definitely isn’t right and Hornady is going to push it off on the Barrel mfg’s...there is going to be a lot of pissed off customers over the bullet getting stuck. By the time I have the funds to do my ARC I hope they get this figured out.
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#40
This thread , for ME

Is officially CLOSED / sent back my Proof barrel to Rainier Arms yesterday , requesting they defect it based on inability to shoot factory loading and proof stating it is possible the freebore is too tight.

Back to waiting for my other barrel to arrive ................

Thanks for all your help and support , it’s been a crazy month
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